Transmission gear for motor vehicles



Jam. 2, 1923.

B. LAWRENCE TRANSMISSION GEAR FOR MOTOR VEHICLES.

2 SHEETS-SHEET i F LED MAR. 20, I 922 Jan, 2, i923. EAALQW B. LAWRENCE.

TRANSMISSION GEAR FOR MOTOR VEHICLES.

F1 LED MAR. 20, 1922. 2 sHEETs-sHElfi 2 Patented den. 2, 11231.

BENJAMIN LA'WHENCE, OF LONDON, ENGLAND.

TRANSMISSION enen non MOTOR vnnrcnns Application filed March 220, 1922.

To all whom it may concern Be it known that I. BENJAMIN Lawnnrzon, asubject of the King of Great Britain, and resident of London, England,have invented certain new and useful Improvements in Transmission Gearsfor Motor Vehicles, oi which the following is a specification.

This invention relates to transmission gear for motor vehicles and hasfor its objcct to provide means for preventing the unintentionalengagement of the driving gear, more particularly in that type ofvehicle where a pedal lever is used to control both the clutch and theepicyclic or low gear. a i

It is usually arranged that such a pedal lever, when in its raisedposition, allows engagement of the direct driving clutch. Slightlydepressing the pedal causes the clutch to be released, so that the driveis provided according to the present invention amovabl'e stop which maybe brought into such a position that it engages with the pedal lever orwithsome part connected thereto when the pedal has been depressedsufficiently to release the driving clutch, and prevents furtherdownward movement thereof. Thus the low driving gear cannot be broughtinto operation without first moving the stop out of its operativeposition.

An operating rod actuated from a point accessible to the driver isconnected to the movable stop so that it may be readily moved, and thesaid stop is so arranged that when released it is returned by a springinto its operative position.

Moreover a locking device is provided which retains the movable stop inits in operative position, after having been so placed, until the pedalhas first been depressed past its central or free position, suchdepression of the pedal causing the release of the movable stop. Theparts are so arranged that the movable stop cannot return Serial no;545,292.

to its'operative position, although released,

until the pedal has been allowed to rise to about its central positionafter having been further depressed. Thus the low gear may be engagedandreleased repeatedly without the necessity of operating the movable stopeach time, unless the pedal is allowed to rise. to its central position.

in order that my invention may be more readily understood andconveniently carried into eifectl have illustrated an apparatusconstructed in accordance therewith in the accompanying drawing whereinsimilar reference characters relate to corresponding partsthroughout'the several figures thereof and l11 hlCl1' Figure l is asectional elevation of such an apparatus arranged on theiootboard'oi avehicle withthe operating rod and actuating trlgger therefor attached tothe steering column, the positions assumedin the slightly depressed orfree engine and the low gearor lowerpositions of'the pedal'being shewnin full and dottedlines respectively. c i

Figure 2 isa plan view of the movable stop and the locking device withthe protecting cover plates removed.

Figure 3 is a frontelevationshcwing the same parts with the cover platesin position thereon;

Referring to the said drawings'it will-be seen that the apparatustherein illustrated comprises a base plate a attached-by any suitablemeanssuch at the set screws 5 and the plate 0 to the footboard d of amotor vehicle,.the dash board of'w-hich is indicated at e andthe'steering column at ft 0 representing the pedal for control of theclutch and the gears.

The movable stop previously referred to, in the embodiment illustrated,takes the form of a plate 2' slidably mounted on the base a and normallyprojected forwardly or in the path of the lug j carried by the pedal 9by the helical spring 70 encircling the rod Z rotatably mounted in thestandards m integral with the base plate a and provided with the fixedcollars n which prevent longitudinal movement of the rod Z.

One end of the rod Z is bent downwards the rod 1) being secured to thetrigger lever '2' pivotally mounted at s to the steering column It willbe apparent that the rod Z by its engagement in the slot 0 and under theinfluence of the spring 70 normally presses the plate forwardly into theposition shewn in full lines in Figure 1 and thus into the path of thelug j preventing further clownward movement of the pedal When it isdesired to put in the low gear the trigger a is pulled upwards whichaction by means oi? the rod 11 rotates the rod Z against the action ofthe spring is and thus withdraws the plate tout oi the path of the lug jinto the position shewn in dotted lines, allowing the pedal 9 to befurther depressed and bring the low driving gear into operation.

With the apparatus so far described the release of the trigger T willautomatically cause the plate 71 to return to its operative position butas previously indicateda further feature of the invention resides in theprovision ota locking device which will retain the movable stop or platea in its inoperative position until released by the operation of thepedal 9.

This locking device comprises a cam member 2? provided with the stop pinit and mounted on the outer end of the rod 0), pivotally mounted in thestandards to integral with the base plate a and having the fixed collarsa: to'prevent its longitudinal move ment. The rod 12 is encircled by ahelical spring z which normally maintains it in such a position as tourge the cam 23 :upwards against the front edge and in the path of theforward movement oi: the plate '5 the stop to limiting this upwardmovement of the cam t. Thus when the plate is withdrawn as previouslydescribed the cam t retains it in its inoperative position.

Ondepression of the pedal 9 beyond the position shown in Figure 1 thelug 7' strikes the cam 25 and moves it out of the path of the plate 2'.The plate i will then abut against the curved front of the lug j so thatthe low gear may be engaged and disengaged as often as desired withoutoperating the plate by means of the trigger 7a When the requisite speedof the vehicle has been at tained the pedal g is released and returnsautomatically to its normal position thus allowing the plate i to returnto its operative position under the influence of the spring 75.

The plate i and the rods Z and o are enclosed within suitable housings2, 1 and 2, respectively. attached by screws 3 to the base plate a.

The plate 2' may be permanently held out of its operative position ifdesired by any simple and. suitable means such as for example by a pinattached by a chain to the plate and adapted to be passed through ahole, in the same and a hole in the base plate registering therewithwhen the plate is in its inoperative position.

What I claim is 1. Transmission gear for motor vehicles comprising incombination a clutch and low gear pedal, a slidably mounted movableplate, a spring-urged rod engaging said plate and maintaining the samein its operative position in the downward path of said pedal, aconnecting rod operatively con nected to said spring-urged rod and apivotally mounted trigger secured to said connecting rod.

2. Transmission gear for motor vehicles comprising in combination, aclutch and low' gear pedal, a slidably mounted movable plate, aspringurged rod engaging said plate and maintaining the same in itsope-rative position in the downward path of said pedal, a connecting rodoperatively connectedto said spring-urged rod and a pivotally mountedtrigger secured to said connecting rod, and a locking cam carried by asecond spring-urged rod for retaining said movable plate in itsinoperative position.

In testimony whereof I afiiX my signature.

BENJAMIN LAlVRENCE.

